The present invention relates to a method and a device for determining the rectilinearity of guide rails in, for example, an elevator system.
Guide rails serve for the guidance of objects, for example the guidance of elevator cars. Usually several guide rails are connected into a rail strand. Elevator cars are usually conveyed while suspended at cables and are guided by way of guide elements along the rail strand. In that case the rectilinearity of the guide rails is of significance, since the travel comfort depends thereon. Departures from rectilinearity of the guide rails lead to vibrations in the elevator car. Such vibrations make themselves strongly noticeable not only in the case of a long rail strand, but also in the case of fast elevator cars, for example in high buildings, and are regarded by passengers as detrimental.
The patent document EP 0 498 051 shows a method and a device according to which the spacing of a guide rail from a frame is measured by a spacing detector. The frame is in contact with the guide rail by way of two mutually spaced guides and is moved over the guide rail. The spacing detector and frame are connected together. The spacing detector is in contact with the guide rail by way of a roller and measures changes in spacing between the guide rail and the frame. This measuring device is mounted on the elevator car and checks installed guide rails in special test travels. A downstream straightening device corrects specific non-rectilinearities in the guide rail system, for which purpose the respective guide rails are detached from their mounting in the elevator shaft. The high cost connected with the checking and straightening of the guide rails is disadvantageous in this method and this device.